Patients with multiple sclerosis and fatigue may have abnormal sleep cycles


CHICAGO Fatigue in patients with multiple sclerosis may be related to abnormal or disrupted sleep cycles, according to an article in the April issue of The Archives of Neurology, one of the JAMA/Archives journals.

According to the article, fatigue is the most frequent symptom of multiple sclerosis (MS) and is often difficult to treat. Fatigue is experienced by 76 percent to 92 percent of MS patients and is often profoundly debilitating, the article states.

Hrayr P. Attarian, M.D., of the University of Vermont, Burlington, and colleagues investigated whether circadian rhythm abnormalities or sleep disturbances exist in patients with MS and if they correlate with fatigue and daytime sleepiness. Circadian rhythms are the cycles of sleep and wakefulness, controlled by part of the brain.

The researchers studied 15 patients with MS and fatigue compared with 15 patients with MS without fatigue and 15 healthy people without MS.

The researchers found that of the 15 patients with MS, two had delayed sleep phase, ten had disrupted sleep, and three had normal sleep. One of the 15 non-fatigued MS patients had irregular sleep cycles, two others had disrupted sleep and 12 had normal sleep. All 15 participants without MS had normal sleep. Nine patients with MS and fatigue scored high on a sleep scale test, indicating excessive daytime sleepiness. Only two patients with MS without fatigue scored high on this test. None of the participants without MS were fatigued.

The researchers found a relationship between fatigue and abnormal sleep cycles or disrupted sleep, and between excessive daytime sleepiness and fatigue in MS patients.

"In our series of patients with MS, there was a significantly high probability of a relationship between fatigue and disrupted sleep or abnormal sleep cycles," the authors write. "These abnormalities may be playing a role in the pathophysiology of poorly understood and disabling MS fatigue."

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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